MultiThreadMapDisplay.h

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/*  Copyright (C) 2008 National Institute For Space Research (INPE) - Brazil.

    This file is part of the TerraLib - a Framework for building GIS enabled applications.

    TerraLib is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License,
    or (at your option) any later version.

    TerraLib is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with TerraLib. See COPYING. If not, write to
    TerraLib Team at <terralib-team@terralib.org>.
 */

/*!
  \file terralib/qt/widgets/canvas/MultiThreadMapDisplay.h

  \brief A multi thread Qt4 widget to control the display of a set of layers.
*/

#ifndef __TERRALIB_QT_WIDGETS_INTERNAL_MULTITHREAD_MAPDISPLAY_H
#define __TERRALIB_QT_WIDGETS_INTERNAL_MULTITHREAD_MAPDISPLAY_H

// TerraLib
#include "MapDisplay.h"

// Qt
#include <QtCore/QMap>
#include <QtCore/QString>
#include <QImage>

// STL
#include <vector>

namespace te
{
  namespace qt
  {
    namespace widgets
    {
// Forward declarations
      class DrawLayerThread;

      /*!
        \class MultiThreadMapDisplay

        \brief A multi thread Qt4 widget to control the display of a set of layers.

        \ingroup widgets

        \sa MapDisplay, te::map::AbstractMapDisplay, te::map::MapDisplay
      */
      class TEQTWIDGETSEXPORT MultiThreadMapDisplay : public MapDisplay
      {
        Q_OBJECT

        public:

          /** @name Initializer Methods
           *  Methods related to instantiation and destruction.
           */
          //@{

          /*!
            \brief It constructs an empty multi thread map display with the given dimensions which is a child of parent, with widget flags set to f.

            \param size The map display size.
            \param showFeedback A flag that indicates if the map display will show drawing feedback.
            \param parent The widget's parent.
            \param f Widget window flags.
          */
          MultiThreadMapDisplay(const QSize& size, const bool& showFeedback = true, QWidget* parent = 0, Qt::WindowFlags f = 0);

          MultiThreadMapDisplay(QWidget* parent = 0, const bool& showFeedback = true, Qt::WindowFlags f = 0);

          /*! \brief Destructor. */
          ~MultiThreadMapDisplay();

          //@}

          /** @name AbstractMapDisplay Methods
           */
          //@{

          void setExtent(te::gm::Envelope& e, bool doRefresh = true);

          void refresh();

          //@}

          /*!
            \brief Transforms the given point, in screen coordinates, to a point in world coordinates.

            \param p A point in screen coordinates.

            \return The point in world coordinates.

            \note This method will return a null point if the transform can not be done.
          */
          virtual QPointF transform(const QPointF& p);

          void setSynchronous(bool on);

          void updateLayer(te::map::AbstractLayerPtr layer);

        private:

          void updateTransform();

        protected slots:

          void showFeedback(const QImage& image);

          void onDrawLayerFinished(const int& index, const QImage& image);

        signals:

          /*!
            \brief This signal is emitted when the draw process ends. i.e. when all layers have been drawn.

            \param errors A map that indicates the errors that could be occurred during the draw process. i.e layer id -> error message

            \note The signal parameter maps the layer id (that generated the error) to an error message.

            \note The signal parameter can be empty. It indicates that no error occurred.
          */
          void drawLayersFinished(const QMap<QString, QString>& errors);

        private:

          /** @name Copy Constructor and Assignment Operator
           *  Copy constructor and assignment operator not allowed.
           */
          //@{

          /*!
            \brief Copy constructor not allowed.

            \param rhs The right-hand-side copy that would be used to copy from.
          */
          MultiThreadMapDisplay(const MultiThreadMapDisplay& rhs);

          /*!
            \brief Assignment operator not allowed.

            \param rhs The right-hand-side copy that would be used to copy from.

            \return A reference to this object.
          */
          MultiThreadMapDisplay& operator=(const MultiThreadMapDisplay& rhs);

          //@}

        protected:

          std::list<te::map::AbstractLayerPtr> m_visibleLayers; //!< The set of visible layers.
          std::vector<DrawLayerThread*> m_threads;              //!< The set of threads used to draw the layer list.
          std::map<int, QImage> m_images;                       //!< The set of images built by each thread. It will be used to compose the final result, keeping the layer list order.
          bool m_showFeedback;                                  //!< A flag that indicates if the map display will show drawing feedback.
          QMatrix m_matrix;                                     //!<  Used to convert screen coordinates to world coordinates.
          bool m_synchronous;                                   //!< A flag that indicates if the map display is  synchronous or asynchronous.
      };

    } // end namespace widgets
  }   // end namespace qt
}     // end namespace te

#endif  // __TERRALIB_QT_WIDGETS_INTERNAL_MULTITHREAD_MAPDISPLAY_H